Abstract: There is provided an air filter element which is used by fitting a central opening in its end plate on a cylindrical portion projecting into a casing, wherein the air filter element has a novel seal construction (end plate). An end plate (10) closing the end surface of a hollow cylindrical filter portion (2) includes a soft inner peripheral seal portion (11) capable of sticking to the outer surface of a cylindrical member (33) and a rigid closure portion (13) which is disposed on the outer periphery side of the inner peripheral seal portion and in which the end surface of the filter portion is embedded, the end plate being of composite construction in which the inner peripheral seal portion (11) and the closure portion (13) are integrally molded. On the outer periphery side of the inner peripheral seal portion (11), a groove (12) axially extending from an end surface (10a) of the end plate is formed along the opening.

Abstract: A rotary ozonizer includes a drive motor for driving a rotor and an air compressor. The rotor is housed in a cylindrical body serving as an stationary electrode. The rotor is secured to a rotor shaft extending through the cylindrical body and rotating upon rotation of the motor through an insulating joint. The rotor serves as a rotary electrode, and provides an electrical discharge spaced relative to the cylindrical body. Electrical power supply portions are connected to the rotor and to the stationary electrode, and end plates are provided to cover open ends of the cylindrical body. The end plates rotatably support the rotor shaft. The motor, the insulating joint, the cylindrical body and the compressor are aligned coaxially in one of the embodiments of the present invention.

Abstract: A rotary ozonizer has a base, a disk-shaped stationary electrode mounted on the base, and a rotary electrode unit disposed over the stationary electrode in face-to-face relation to form an electric discharge clearance. The rotary electrode unit comprises a plurality of radially outwardly extending arms, and upstanding blades fixed to the radially outer portions of the arms, respectively. When the rotary electrode unit is rotated about a vertical axis by a motor and a high voltage is applied between the electrode and electrode unit, an electric discharge takes place to ozonize the oxygen in said electric discharge clearance, and the thus produced ozone is supplied by the blades out of the ozonizer.